What are the causes of elevated troponin levels?

Causes of Elevated Troponin Levels

Elevated troponin levels can be caused by numerous cardiac and non-cardiac conditions beyond acute myocardial infarction, with tachyarrhythmias, heart failure, hypertensive emergencies, critical illness, myocarditis, Takotsubo syndrome, and valvular heart disease being the most frequent causes. 1, 2

Cardiac Causes of Troponin Elevation

• Acute Coronary Syndromes

  • Type 1 myocardial infarction (STEMI and NSTEMI)
  • Note: Elevations beyond 5-fold the upper reference limit have high (>90%) positive predictive value for acute type 1 MI 1

• Other Cardiac Conditions

  • Tachyarrhythmias/bradyarrhythmias 1, 2
  • Heart failure (acute and chronic) 1, 2
  • Structural/valvular heart disease (e.g., aortic stenosis) 1, 2
  • Myocarditis 1, 2
  • Takotsubo cardiomyopathy 1, 2
  • Cardiac contusion 1
  • Cardiac procedures (CABG, PCI, ablation, pacing, cardioversion, endomyocardial biopsy) 1
  • Hypertensive emergencies 1, 2
  • Infiltrative diseases (amyloidosis, hemochromatosis, sarcoidosis, scleroderma) 1

Systemic/Non-Cardiac Causes

• Pulmonary Conditions

  • Pulmonary embolism 1, 2
  • Pulmonary hypertension 1, 2

• Renal Disease

  • Renal dysfunction and associated cardiac disease 1, 2
  • Note: Elevations should not be primarily attributed to impaired clearance but to underlying cardiac conditions 1

• Critical Illness

  • Sepsis/shock 1, 2
  • Burns 1

• Neurological Events

  • Stroke 1, 2
  • Subarachnoid hemorrhage 1, 2

• Endocrine Disorders

  • Hypo- and hyperthyroidism 1, 2

• Other Systemic Conditions

  • Extreme endurance exercise 1, 2
  • Rhabdomyolysis 1
  • Myocardial drug toxicity or poisoning (e.g., doxorubicin, 5-fluorouracil, herceptin, snake venoms) 1

Interpreting Troponin Elevations

• Troponin levels should be interpreted as quantitative markers of cardiomyocyte damage:

  • Higher levels indicate greater likelihood of MI 1
  • Elevations up to 3-fold the upper reference limit have limited (50-60%) positive predictive value for AMI 1
  • Rising and/or falling patterns help differentiate acute from chronic damage 1

• Important considerations:

  • Detectable troponin levels are common in healthy individuals with high-sensitivity assays 1
  • Sex-specific 99th percentile thresholds should be used 2
  • ECG findings should be correlated with troponin results 2

Clinical Implications

• When elevated troponin is detected, consider the clinical context:

  • Absence of ECG changes with very high troponin values raises suspicion for non-ACS causes 2
  • Serial measurements showing rising/falling pattern (≥20% change) suggest acute myocardial injury 2
  • Higher initial and peak troponin levels are more likely associated with ACS than non-ACS causes 3

• Remember that troponin elevation indicates cardiac injury but does not define the cause of injury 4

  • Elevated troponin predicts adverse outcomes regardless of cause 2
  • Treatment should target the underlying cause rather than automatically initiating antithrombotic therapy for non-ACS elevations 5

When evaluating elevated troponin, a systematic approach considering both cardiac and non-cardiac causes is essential for accurate diagnosis and appropriate management.